edible garden
BENEFICIAL BUGS
Why you should love some creepy-crawlies.
WRITTEN BY SUE EDMONDSON
ILLUSTRATIONS BY REED DEWINTER
Predators and parasites! The words conjure sci-fi monstrosities whose goal is destruction of the earth. In the gardening world, these dreadful-sounding creatures actually can be welcome insects. Some destroy all right, but only the pests that harm our plants. They, along with pollinators and composters, truly are the gardener’s best friends.
The Good Guys
Many are as recognizable as houseflies — ladybird beetles (more commonly called ladybugs), praying mantises, dragonflies, green lacewings, bees, butterflies, and worms.
Some good guys you might be tempted to, well, squish are spiders, predacious flies (the robber fly, for example, with its bulbous red eyes and hunched back), and parasitic wasps, the tiny cousins to hornets and yellow jackets.
“There are too many to name, given the number of species of insects,” says Nevada state entomologist Jeff Knight.
But they all have one thing in common: a hunger for plant-destroying pests.
The Pests
“Aphids are the most common,” Knight says. “Just about every plant is susceptible to them.”
Look for clusters of tiny critters on the undersides of misshapen leaves. Other miniatures, such as flower-destroying thrips or mites, are so teeny they may be hard to identify. Larger culprits include earwigs (beware of pincers), tomato-eating hornworms, and grasshoppers.
Promoting Beneficials
Dr. Heidi Kratsch, University of Nevada Cooperative Extension horticulture specialist, says there are two critical components to attracting and keeping good insects.
“First, you need to be careful with pesticides,” she says. “Any broad-spectrum pesticide will kill all insects, including beneficials. If you must use chemicals, use ‘soft’ ones, like dormant oils or insecticidal soap, because they only last about 24 hours. Second, you have to tolerate a level of harmful insects because the beneficials live on them. You’re going for a balance.”
If you buy insects, purchase larvae whenever possible, Kratsch advises.
“Ladybird beetle larvae can eat hundreds of aphids before becoming adults,” she says. “Larvae are hungry! Also, when larvae mature, the adults will be less inclined to leave your yard. If they don’t grow up where you put them, they probably won’t stay.”
Provide water and shelter, too.
“A bird bath or small dish of water will work,” she says. “Plant flowers, particularly those native to your area. Insects will use them for shelter.”
Bees, Butterflies, and Worms
“Pollinators are necessary for flower and fruit production,” says Sara Anderson of All Seasons Lawn & Landscaping in Reno. “Bees and butterflies are both excellent pollinators. If you plant brightly colored flowers, they will come.”
Anderson, who also is president-elect of the Nevada Landscape Association, suggests adding red or black worms to your garden soil.
“Their castings make excellent compost,” she says.
First Things First
“Before you buy predators, know your pests,” Knight says. “If they aren’t interested in eating the insects in your garden, your neighbors will be the beneficiaries of your investment.”
Freelance writer Sue Edmondson writes for various publications in Nevada and California. She recently hung up her fly swatter, and is learning to squelch the urge to squish the spiders in her garden.
To figure out whether an insect is friend or foe, Knight and Kratsch advise visiting http://www.unce.unr.edu . Also, visit www.Managenvpests.info and click on the insect photos sidebar. If you can’t match your insect, Knight may be able to identify it for you. For details, call 775-353-3767.
